1. Field of the Invention
The invention relates generally to portable electronic devices such as a handheld electronic device, and, more particularly, to a charger unit for charging the battery of and/or providing power to the electronic device that includes a system for protective storage of an adapter plug used in connection with the charger unit.
2. Description of the Related Art
Numerous types of handheld electronic devices are known. Examples of such handheld electronic devices include, for instance, personal data assistants (PDAs), handheld computers, two-way pagers, cellular telephones, and the like. Many handheld electronic devices include and provide access to a wide range of integrated applications, including, without limitation, email, telephone, short message service (SMS), multimedia messaging service (MMS), browser, calendar and address book applications, such that a user can easily manage information and communications from a single, integrated device. These applications are typically selectively accessible and executable through a user interface that allows a user to easily navigate among and within these applications. Many handheld electronic devices also feature wireless communication capability, although many such handheld electronic devices are stand-alone devices that are functional without communication with other devices.
Such handheld electronic devices are generally intended to be portable and thus are relatively small. In addition, most portable handheld electronic devices are powered by a rechargeable battery, such as a rechargeable lithium battery. As is known, such rechargeable batteries may be recharged using a charger unit having a plug (male electrical connector) that is inserted into an AC electrical outlet such as those available in a home or office. Specifically, in a typical recharging situation, the handheld electronic device having the reachable battery connected thereto is electrically connected, such as by a wire connection or by mated integral electrical contacts, to the charger unit, and current drawn from the AC electrical outlet by the charger unit is used to produce a chemical reaction inside the rechargeable battery, thereby recharging it. In addition, many such charger units may be used to provide power to handheld electronic devices directly (while being used) without use of the rechargeable battery.
One common problem with known charger units is that they may be easily damaged. In particular, the metal prongs of many charger unit plugs are susceptible to damage, such as the bending or breaking thereof, especially when the user is traveling.
In addition, as is known, electrical systems differ around the world, utilizing differing voltage levels and differing connection mechanisms (e.g. different plug configurations). In order to enable a user to recharge a battery using any one of a number of such different electrical systems, such as when the user travels to a different country, some current charger units are provided with removable and replaceable adapter plugs, each one being suitable for use in connection with a different electrical system. The adapter plugs not in use must be separately stored by the user, and are often susceptible to damage and being misplaced.
FIGS. 1 and 2 are front and isometric views, respectively, of one known charger unit 5 for charging the battery of a handheld electronic device. Charger unit 5 utilizes removable and replaceable adapter plugs, such as plug 10 shown in FIGS. 2, 3 and 4, to enable it to be used in different countries in connection with different electrical systems. Plug 10, for example, is a plug suitable for use in connection with the standard 110 volt electrical system utilized in North America. Plug 10 includes metal prongs 15A and 15B connected to and protruding from the front side 20 of base 25. Base 25 is typically made of plastic and includes tongues 30A and 30B extending from opposite sides thereof. In addition, lip portion 35 is located at the bottom end of the back side 40 of base 25. As seen in FIG. 4, contacts 45A and 45B are included within base 25 and are in electrical contact with prongs 15A and 15 B, respectively.
Referring again to FIGS. 1 and 2, charger unit 5 includes a housing 50 in which the electrical circuitry of charger unit 5 is provided. Front face 55 of housing 50 is provided with a recess 60 having grooves 65A and 65B located on opposite sides thereof. A latch 70 is provided adjacent to the bottom end of recess 60. Contacts 75A and 75B are provided within recess 60, and are connected to the electrical circuitry housed within housing 50. Plug 10, and other plugs suitable for use in other electrical systems, may be selectively attached to housing 50 by sliding tongue 30A within groove 65A and tongue 30B within groove 65B. When the bottom of plug 10 approaches the bottom of recess 60, latch 70 engages lip portion 35 to hold plug 10 in place. In this state, which is shown in FIG. 5, contact 45A engages contact 75A and contact 45B engages contact 75B. Latch 70 may be actuated by button 80 provided on front face 55 of housing 50 in order to detach plug 10 therefrom.
As described above, the problem with a charger unit such as charger unit 5 is that prongs 15A and 15B are left unprotected and thus are susceptible to being bent or broken, both when plug 10 is attached to and detached from charger unit 5. Further, when the prongs are left unprotected, they could poke through the side of a computer case, briefcase or writing folio. In addition, when plug 10 is detached from charger unit 5, it is susceptible to being lost. One known prior art charger system has attempted to address these problems by including a rotatable plug portion (having NA-type prongs for insertion into an outlet) that may be rotated approximately 90 degrees into a protective position within the housing of the charger unit in which the prongs no longer extend outwardly from the housing. While this system does provide protection to the prongs of the NA plug used for charging, it still requires multiple different types of plugs to be swapped in and out for other type electrical sockets as desired. In another prior art charger system that protects an NA plug, the NA plug is permanently attached and rotates 90 degrees in the plane of the centerlines of the prongs. Both of these prior art charger systems can be used with generic adapter plugs that may slide over the prongs in the stowed position; however, these generic plugs are usually quite large and bulky, since they may be used for much heavier electrical power loads than necessary for the AC adapters for mobile electronic devices. Thus, there is a need for a charger unit for an electronic device such as a handheld electronic device that can accommodate and utilize multiple different types of plugs as selected by the user and provide protection to such plugs when not in use.